Automatic slide projector



Oct 4, 1966 H. T. ROBINSON 3,276,314

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By @%/M HTDRNEYS Oct 4, 1966 H. T. ROBINSON 3,276,314

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AUTOMATIC SLIDE PROJECTOR Original Filed Feb. 1962 17 Sheets-Sheet 10 Efizrberi IRobinson IN V EN TOR.

Oct. 4, 1966 H. T. ROBINSON 3,276,314

AUTOMATIC SLIDE PROJECTOR Original Filed Feb. 23, 1962 17 Sheets-Sheet 11 HerberiflZRobinson INVENTOR.

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ATTORNEYS Herbei'IIRob Oct. 4, 1966 H. T. ROBINSON AUTOMATIC SLIDE PROJECTOR Original Filed Feb, 23, 1962 Oct. 4, 1966 H. T. ROBINSON AUTOMATIC SLIDE PROJECTOR l7 SheetsSheet 15 Original Filed Feb. 23, 1962 Nam EIerberlT. Robin-son JNVENTOR.

3 WnH mafilwriilz AT IORNEY'Y Oct. 4, 1966 H. T. ROBINSON AUTOMATIC SLIDE PROJECTOR l7 Sheets-Sheet 16 Original Filed Feb. 23, 1962 Qh z qvw n o l m m w mm m w 0 V v R m N a T W 1L r w e a b 4. r m m M Q m %N E w mmzoEmoa 3 5? m mm x m m mmrFSIm m wEXmQE mo m ZOPGMEQ w hmomwzfii u. M075 0 Q (Q m wmawmmmn w XwnZS m mh A U, ATTORNEYS Oct. 4, 1966 H. T. ROBINSON RESISTOR MOTOR REVERSE FORWARD Pawsnswrrcn Z AUTOMATIC SLIDE PROJECTOR Original Filed Feb. 23, 1962 17 Sheets-Sheet l 7 REMOTE jnscs rqcls A avscnnms SOLENOID 4o SOLENOID CYCLE R EVERSE G) FOCUSING MOTOR Herbert '11 Robinson IN V EN TOR. 7 '7 By K? 7fif/6z([ .ATTORNEw United States Patent 25 Claims. (Cl. 88-27) This application is a division of US. patent application Serial No. 175,216 for an Automatic Slide Projector, filed on February 23, 1962, by Herbert T. Robinson.

This invention relates generally to slide projectors, and more specifically to an improved automatic slide projector selectively controlled by automatic or manual means.

One of the primary objects of the present invention is to provide an automatic slide projector that is jam-proof in operation.

Another object of this invention is the provision of an automatic slide projector having a vertical gravity slide feed means.

Still another object of this invention is the provision of a slide projector having a circular slide tray.

A more specific object of the invention is to provide an automatic slide projector having a circular slide tray mounted on top of the projector, and adapted upon rotation to feed the slides by gravity to the slide-viewing position.

A further object of the invention is to provide an improved slide projector having a slide tray mounted on the top thereof in an unobstructed position where it is easily accessible for slide editing and removal, and in which the slide compartment members and film gate index are in clear view at all times.

Still another object of the invention is the provision of an improved slide projector in which any slide therein may be edited at any time during projection.

A further object of the invention is to provide a slide projector that greatly simplifies the film transport means.

Still another object of the invention is the provision of an improved automatic slide projector having a simplified and improved editing system.

Another object of the invention is to provide a slide projector in which the slides may be edited in the slide tray directly, or the slide tray may be removed and individual slides fed manually into the projector for editing.

Still another object of the invention is to provide a slide projector having a circular slide tray adapted to accept glass, metal or plastic mounts of -inch thickness or less.

Objects and advantages other than those set forth above will be apparent from the following description when read in connection with the accompanying drawings, in which:

FIG. 1 is a perspective view of an automatic slide projector built in accordance with this invention;

FIG. 2 is a fragmentary, rear elevation perspective view of the projector of FIG. 1;

FIG. 3 is a top plan view of the slide projector of FIG. 1 with a slide tray mounted thereon;

FIG. 4 is a view similar to FIG. 3, with the slide tray removed;

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FIG. 5 is a bottom view of the slide tray;

FIG. 6 is a side elevation view of the slide tray of FIG. 5;

FIG. 7 is a bottom view of the slide tray latch apart from the slide tray;

FIG. 8 is a side elevation view of the latch of FIG. 7;

FIG. 9 is a side elevation view in section of the slide retaining ring of the slide tray;

FIG. 16 is a bottom view of the slide projector of FIG. 1 with the bottom plate removed;

FIG. 11 is an enlarged bottom view of one of the components shown in FIG. 10;

FIG. 12 is a top plan view of the component of FIG. 11 turned through an angle of FIG. 13 is a segmental front elevation view of a portion of the component of FIG. 12 with a part of the wall broken away and a cam and portion of a lever omitted for purposes of clarity;

FIG. 14 is a front elevation view of the component of FIG. 12;

FIG. 15 is a rear elevation view of the component of FIG. 12;

FIG. 16 is a left side elevation view of the component of FIG. 12;

FIG. 17 is a right side elevation view of the component of FIG. 12;

FIG. 18 is a combination side elevation .and end views of a pair of cams for operating the shutter and slide transport mechanisms;

FIG. 19 is a view similar to FIG. 18 of another pair of cams for operating the pressure pad and tray positioning mechanisms;

FIG. 20 is a view similar to FIG. 18 of still another pair of cams for operating the tray indexing and direction control mechanisms;

FIG. 21 is a side elevation view of the cam and slide transport mechanism with the remaining structure omitted for purposes of clarity, and further showing its normal lowermost position in full lines and its uppermost position in dotted lines;

FIG. 22 is a side elevation view of the cam and shutter mechanism with the remaining structure omitted for purposes of clarity, and further showing its normal open position in full lines and its closed position in dotted lines;

FIG. 23 is a side elevation view of a cam and tray positioning mechanism with the remaining structure omitted for purposes of clarity, and further showing its normal blocking position in full lines and its unblocking position in dotted lines;

FIG. 24 is a side elevation view of a cam and pressure pad mechanim with the remaining structure omitted for purposes of clarity, and further showing its normal closed position in full lines and its open position in dotted lines;

FIG. 24a is a side elevation view of the slide gate and pressure pad of FIG. 24 showing the closed and open positions;

FIG. 25 is a side elevation view of a cam and tray indexing mechanism with the remaining structure omitted for purposes of clarity, and further showing its normal non-indexing position in full lines and its indexing position in dotted lines;

FIG. 26 is a section view taken along line 2626 of FIG. 25;

FIG. 27 is a side elevation view of the cam and direction control mechanism with the remaining structure omitted for purposes of clarity, and further showing its normal inoperative position in full lines and its operative position in dotted lines;

FIG. 28 is a graph showing the relative relationships between the driven mechanisms for one complete cycle of operation;

FIG. 29 is a graph showing the rise and fall of the cams for one complete cycle of operation; and

FIG. 30 is a schematic electrical circuit diagram for the projector.

General description With respect to general function, the improved slide projector of this invention may be operated by either automatic or manual control means of the same general type disclosed in US. Patent No. 2,969,711. The slide projector has means mounted on top thereof for holding a plurality of slides which are to be projected, and means for cyclically indexing the slide holding means in a forward or reverse direction by the automatic or manual means for bringing successive slides in register with a vertically oriented slide or projection gate. The slide in register with the gate is lowered under the influence of gravity by a slide transport means into a viewing position in alignment with the optic system of the projector for projection. During a cycle of operation of the projector, a projected slide, if any, is returned to the slide holding means, the slide holding means indexed, and a different slide lowered by the slide transport means into the viewing position. This projector further has a half-cycle position for editing and random projection in which the slide transport means returns the projected slide, if any, to the slide holding means and is retained in that position. In addition, the indexing means is disabled in the halfcycle position. Consequently, the operator may edit the returned slide or manually move the slide holding means to any desired position for projecting the selected slide upon completion of the cycle of operation.

More specifically, as shown in the drawings, preferably FIGS. 1 and 2, a preferred embodiment of the invention is incorporated in a slide projector 2 having a rectangularly shaped cast frame 4. The front of the projector 2 has a plate 6 secured thereto having a central opening 8 through which a lens barrel 10 extends. The plate 6 further has ventilating slots 12 therein for the passage of air. The front of the projector further has a door 13 pivotally secured to frame 4 and movable by knob 14 into an open position to provide access to a cord-storage compartment 16 seen in FIG. 10. The door 13 further has ventilation openings 18 and louvers 20 through which air is exhausted from the projector. A U-shaped handle 22 is pivotally secured to frame 4 to facilitate carrying the protector 2.

The left side of the projector as seen in FIG. 1 has a focus knob 24 and an elevation knob 26, and further has a cover 28 over an optics compartment 30 as seen in FIG. 10. Cover 28 has louvers 29 therein and is secured to frame 4 by mean-s of a screw 32. The rear of projector 2 as seen in FIG. 2 has a cover plate 34 secured thereto having an index mark 36 for indicating the operating position of a control knob 38. The knob 38 has four positions designated on a flange 40 thereof, one of which is designated manual" in which the operation of the projector is manually controlled by the operator. The three remaining positions may be designated with numbers in dicating intervals between slide changes in automatic operation, for example, the projector may be set by this knob to automatically project each slide for respective 5, 10, or 20-second intervals.

Another plate 42 is secured to the rear of frame 4 and has openings through which push buttons extend for controlling various projector operations. Button 44 controls the editing and random selection projection and is desig nated the Select button. Button 46 is designated the off button and controls the power to the projector. Button 48 is designated the fan button and controls the operation of a projector motor 47 which drives a fan 49, as seen in FIG. 10. Button 50 controls the power to a projector lamp 51, and is designated the low button because it provides a low power illumination, e.g., 300- watt lamp brilliance, by virtue of a resistor in the circuit as seen in FIG. 30. Button 52 also controls projector lamp 51 and is designated the high button because it provides a higher power illumination, e.g., SOD-watt lamp brilliance, by by-passing the aforementioned resistor. Button 54 is designated the rev. button and controls the operation of a slide tray 86 in a reverse direction. Button 56 is designated the fwd. button and controls the operation of slide tray 86 in the forward direction. The plate 42 further has openings to provide access to a power cord receptacle 58 and a remote control receptacle 60.

The top of projector frame 4 has a circular inner rim 62, seen best in FIG. 3, having a lip 64 carrying an index mark 66. The top of frame 4 further has (1) an upwardly projecting central spindle 68 having a beveled top 69, and an opening, not shown, through which a springbiased spindle key 70 extends, (2) an opening 72 (FIG. 4) in register with a slide gate 74, and (3) an opening 76 through which warm air is directed over a plurality of slides in slide tray 86 for prepopping the slides before projection. A tray locating projection 78 extends through a portion of opening 72, and an indexing pawl 80 extends through an opening 82 in frame 4. The function and operation of projection 78 and pawl 80 will be explained in further detail hereinafter. In addition, the top of frame 4 has an opening through which extends a locating pin 84 (to be referred to below in connection with opening 140), and a plurality of nylon inserts 85 (or other bearing surfaces) for supporting tray 86.

The circular slide tray 86 is releasably mounted on spindle 68 within rim 62 and is adapted when indexed in one direction or the other to introduce a slide by gravity into slide gate 74 and into a slide-viewing position in which the slide is in the optical axis of the projector, as will be explained below in more detail. The magazine is manually or automatically cyclically indexed in the forward or reverse direction by incremental distances corresponding to the spacing of successive slide tray compartments (see description of slide tray). A slide changing cycle of the projector generally comprises lifting a slide, if any, from its viewing position back into the tray compartment, indexing tray 86 an incremental distance, and permitting the next slide to be lowered by gravity into the viewing position.

A slide-changing cycle may be initiated and thereafter carried out automatically by a manual depression of reverse or forward push button 54 or 56 during which. cycle the slide tray 86 is indexed in the reverse or forward direction, as the case may be. If either of the push buttons is held down, slide-changing cycles follow each other in rapid succession, thereby permit-ting a scanning action for viewing the slides in tray 86. The slide-changing cycle may also be initiated in the same manner by a remote control switch shown schematically in FIG. 30.

Another means for initiating a slide-changing cycle, during which only forward indexing occurs, comprises the aforementioned control knob 38 for selecting any of a plurality of cycle times, such as 5, 10, and 20 seconds. However, automatic operation at any selected cycle time may be overridden by manually operating push buttons 54, 56 since the mechanism for accomplishing automatic operation and the mechanism for accomplishing manual operation may be operated independently of one another as will be evident from the later discussion.

As indicated heretofore, an editing mechanism is provided for editing slides or to permit random or skip projection by the operator, in which the operator may rotate slide tray 86 to any selected position for showing any particular slide in the tray, the slides being identified by numbers appearing on the tray, as seen in FIG. 3. With this editing mechanism, it is also possible for the operator to show single slides without the use of a slide tray 86, and to provide a secondary way of editing the slides for proper placement in a slide tray.

Optical system Referring to FIG. 10, the projector elements that are located along the optic axis of the system include projection lamp 51, a pair of lenses 90, 92, a heat-absorption glass 94, slide gate 74, and a focusing unit or objective designated generally at 98. The lenses 90, 92 and glass 94 are seated in slots, not shown, in an optical support 86 having approximately the same contour as the lenses and glass. The lenses 9t], 92 and glass 94 are held in their seats by a plurality of spring arms 95 secured to cover 28. The lens barrel of the focusing unit 98 is mounted on a pair of rails, not shown, for reciprocal movement thereon under the control of focusing knob 24 mounted on one end of a shaft 104. A gear 186 is mounted on shaft 104, and meshes with a rack 108 on lens barrel 16.

An automatic power driven focusing means is also provided comprising a bidirectional motor 116 for driving a worm 112 in meshing engagement with a gear 114 mounted on one end of a shaft 116. A worm 118 is mounted on the opposite end of shaft 116 for driving a gear 121) mounted on shaft 104.

Fan 49 draws air into the optics compartment 30 through openings in the base plate, not shown, ventilating slots 12 in plate 6, louvers 29 in cover 28, and opening 72 in the top of frame 4. The air is heated in passing over lamp 551 and the optical elements 98, 94 and expelled by a duct formed by plates 111, 113 and sidewalls 122, 123; through louvers in door 13. A part of this air is expelled through a duct 127 and opening 76 in the top of frame 4 as seen in FIG. 4 for passage through a portion of slide tray 86 for preheating the slides therein.

Slide tray The slide tray 86 as seen best in FIGS. 1, 3, 5-8 and 9 comprises a cylindrical molded portion having concentric plastic shells 119, 124 (see FIG. 3). One end of shell 119 is closed off to form a base 131, and the tops of shells 119, 124 are joined together by spacers 117 to form a plurality of spaced compartments. In the embodiment shown, there are eighty-one equally spaced compartments. Each spacer 117 has a notch 115 therein to facilitate the insertion and removal of slides into and out of the compartments. The outer shell 124 has a peripheral rim 126 containing raised numerals as shown in FIG. 3, corresponding to and designating the compartments. Corresponding indexing means, in this embodiment pins 129 (FIG. 6), depend from rim 126. The 0 compartment has a bridge 128 extending thereacross to prevent the insertion of a slide therein from the top for a purpose to be explained hereinafter. All of the remaining compartments are open at both the top and the bottom.

The outer periphery of base 131 of the molded portion of slide tray 86 provides an annular shoulder 138 as seen in FIG. 5 for supporting another portion of slide tray 86 shown as an annular metal disc 132. The disc is rotatable on shoulder 13%, and is retained thereon by the heads of three screws 134. Disc 132 further has anopening 138 through which heated air expelled from projector opening 76 is directed when the tray 86 is properly mounted on projector 2 for operation, for circulating heated air over the slides for preheating the slides in tray 86. Opening 138 has radially extending notches 136 cooperating therewith to form a passageway through which the slides can pass from tray 86 to slide gate 74. At this point, it should be noted that if bridge 128 were omitted, any slide introduced into the 0 compartment would fall out of slide tray 86 through the passageway when the 0 compartment is in alignment with the passageway.

Disc 132 further has an opening 140 adapted to cooperate with pin 84 for fixedly positioning disc 132 on projector 2 as will be explained hereinafter.

A metal latch 142 as best seen in FIGS. 7 and 8 has oppositely extending tabs 143, 144 slidably movable in complementary openings, not shown, in base 131, which guide the latch for reciprocal movement in a radial direction. The latch 142 further has a pair of spring fingers 148, one end of which are adapted to co-operate with a shoulder 158 of base 131 to urge latch 142 to a latched position in which tab 144 enters'a pair of spaced notches 149 along the inner periphery of disc 132 for releasably holding the disc in a fixed position with respect to base 131. In this position, the passageway formed by notches 136 in disc 132 is in register with the 0 compartment. The opposite ends of fingers 148 co-operate with abutments 152 of base 131 which provide a stop for latch 142 when moved to its unlatched position.

The base 131 has a central opening 1.54 (FIG. 5) having a notch 156 along its inner periphery or rim in alignment with tabs 143, 1 14, and further in alignment with a notch 158 in rim 126 at the location of the O compartment as best seen in FIG. 5. The latch 142 also has an opening 161 which is offset out of alignment with opening 154 when in the latched position, but is in register with opening 154 in the unlatched position. When slide tray 86 is initially placed on top of frame 4, spindle 68 extends through openings 154, 160, and rim 126 of tray 86 will bear on lip 64 and key 70 allowing manual rotation of tray 86 by the operator. The tray is rotated until notches 156, 158 align with lip 64 and key 70 respectively, and are received thereby, causing tray 86 to drop until pins 129 engage inserts 85. As tray 86 drops into engagement with inserts 85, beveled portion 69 of spindle 68 cams latch 142 into its unlatched position. The tray 86 is now in a proper loaded position with the O compartment in register with index 66. Also, in this position pin 84 extends through disc opening 140 for fixedly positioning disc 132 with notches 136 of its slide passageway in register with gate 74.

During projection, disc portion 132 remains fixed and the molded portion comprising shells 119, 129, base 131 and spacers 117 is indexed as a unit relative thereto to successively bring the slides in register with the disc passageway. With disc 132 releasably held by latch 142, the operator is in a position to load slide tray 86 with cardboard, glass, metal, plasticor any other suitable type slides which fit within the spaces between spacers 117. The slides are retained in the compartments by a slideretaining cover ring 159, as seen in FIG. 9, of molded plastic or other suitable material. This cover fits within shell 119 and has a peripheral flange 161 which overlaps the slide compartments to prevent the slides from falling out if the slide tray assembly is tipped upside-down, as in storage, or otherwise. The ring 159 has three angularly spaced, stepped ramps 163 which twist-lock on corresponding lugs 165 (FIG. 3) located on the inner periphery of shell 119. When rotated in one direction, the ring 159 locks to retain the slides in slide tray 86, and when rotated in the opposite direction, it may be removed from tray 86 for slide editing or loading.

Drive mechanism The drive mechanism as seen best in FIGS. 10 and 11 comprises drive motor 47 rigidly secured to a fixed support bracket 168 by means of screws, not shown, extending through spacer elements 164. The motor 47 has a worm 170 for driving a gear 172 that is loosely rotatable on a shaft 174. A gear 176 integral with gear 172 drives a gear 178 which has a gear 180 integral therewith. Gears 178 and 180 are rotatably mounted on a fixed spindle 181 secured to a wall 179, and gear 180 further drives a gear 182 having a timing wheel 184 inte- 

1. A PROJECTOR FOR PROJECTING SLIDES DISPOSED IN A SLIDE TRAY HAVING TWO RELATIVELY MOVABLE PORTIONS SECURED TO ONE ANOTHER AS AN ASSEMBLED UNIT, THE PORTIONS OF THE TRAY COACTING TO RETAIN SLIDES IN THE TRAY DURING STORAGE, ONE OF THE PORTIONS OF THE TRAY HAVING A PASSAGEWAY THROUGH WHICH THE SLIDES ARE ADAPTED TO PASS SUBSTANTIALLY VERTIALLY, ONE AT A TIME, IN COORDINATION WITH RELATIVE MOVEMENT OF THE PORTIONS, WITH AT LEAST ONE OF THE REMAINDER OF THE SLIDES HELD IN THE TRAY BY THE ONE PORTION, ANDPROJECTOR COMPRISING: A PROJECTION GATE, MEANS FOR FIXEDLY HOLDING ONE PORTION OF THE SLIDE TRAY RELATIVE TO THE PROJECTOR WITH THE PASSAGEWAY IN SUBSTANTIALLY VERTICAL REGISTER WITH SAID GATE WHEN THE SLIDE TRAY IS MOUNTED ON THE PROJECTOR, INDEXING MEANS ADAPTED TO MOVE THE OTHER PORTION OF THE SLIDE TRAY RELATIVE TO THE ONE FIXEDLY HELD PORTION THEREOF FOR SUCCESSIVELY BRINGING SLIDES IN 